Automatically releasing well head



April 20, 1948. D. MEDDICK 2,440,015

AUTOMATICALLY RELEASING WELL HEAD 'Filed Jan. 5, 1944 25 27 25 -24 a 26 30 2 4 ,6 2/ l/plll/l/ 20 2 INVENTOR. ZOfiEAl/Y 0. Neva/cw BYQ/QWA Arroe/vz' 1 316: 4

Patented Apr. 20, 1948 AUTOMATICALLY RELEASING WELL HEAD Lorrain D. Meddick, Los Angeles, Calif., assignor to Lane-Wells Company, Los Angeles, Calif a corporation of Delaware Application January 3, 1944, Serial No. 516,833

7 Claims.

My invention relates to automatically releasing well heads, and among the objects of my invention are:

First, to provide an automatically releasing well head which is adapted to permit passage of a cable therethrough while sealing oif the well so that well tools, such as gun perforators, may be lowered or raised in the well bore;

Second, to provide an automatically releasing well head which greatly facilitates operation of gun perforators or similar .well tools in high pressure wells;

Third, to provide a well head which incorporates a latching arrangement adapted to be released when the well tool is lifted forcibly into engagement with the well head, whereupon the packing elements and associated internal parts of the well head are raised with the well tool as it is withdrawn from the well casing;

Fourth, to provide a well head of this character in which the internal parts may be readily reset into position when the well tool is returned to the well casing; and a Fifth, to provide an automatically releasing well head wherein the internal parts, which are normally too small for passage of the well tool, are so arranged that they may be slipped laterally onto the cable in many cases without removal of the well tool and, in any case, without removal of the cable head.

With the above and other objects in view, as may appear hereinafter, reference is directed to the accompanying drawing, in which:

Figure 1 is a fragmentary view of a well casing showing the automatically releasing well head in position-thereon as it appears when a well tool (in this case a gun perforator) has engaged and lifted the internal parts of the well head;

Figure 2 is a longitudinal sectional view of the well head as it appears when the parts are locked in sealing position around a cable;

Figure 3 is a top end view thereof;

Figure 4 is a bottom end view thereof;

Figure 5 is a transverse sectional view thereof through 5-5 of Figure 2; and

Figure 6 is an elevational view of one of the packing elements.

The automatically releasing well head herein illustrated includes a housing I which is screwof a well casing B. It is intended to use the well head in conjunction with a conventional valve (not shown) positioned in the well casing afew feet below the upper end of the casing, the valve having a port therein as large as the easing So that tools which fit the casing may pass through the valve.

The housing I is provided with a packing support member 2 which is in the form of an inverted cup having a closed upper end 3 and cylindrical walls 4 fitting slidably within the housing I. The walls I; are provided with laterallydirected slots 5, each of which receives a latch segment or element 6 having circumferentially extending teeth which are adapted to engage in mating channels or latching recesses i of the housing 5. Ihe latch segments are retained by a garter spring 8 wrapped around the support member 2 and the segments, there being grooves therefor in the support member and latching segments.

Within the packing support member 2 is a tubular keeper mandrel 9 which normally restrains the latch segments 6 from inward movement or retraction in the slots 5 to positions clear of the latching recesses l. The keeper mandrel I} is provided with a release channel In normally positioned below the latching segments. The channel Ill has such dimensions that, when brought opposite the inner ends of the latching segments 6, these segments may then move radially inward, clear of the latching recesses I. The lower end of the keeper mandrel 9 is provided with abase plate I I which is bolted thereto. A spring I2 extends between the base plate II and the closed upper end 3 of the packing support member 2, the spring urging the support member upwardly and the keeper mandrel downwardlyj Downward movement of the keeper mandrel is limited by a shoulder I3 provided within the lower portion of the housing I.

The base plate II is provided with a central hole I4 which accommodates the cable C. The cable 0 may be any conventional wire line or may be a conductor cable such as used to support gun perforators, indicated by D in Figure 1. The base plate II is provided with a radial slot I5 so that the plate may be slipped laterally onto the cable and then bolted or otherwise secured to the keeper mandrel 9. The keeper mandrel 9 has an internal diameter sufficient to pass over the cable head designated E in Figure l. The coil spring I2 may be threaded upon the cable without difficulty.

'The upper end of the packing support member 2 is provided with a split bushing i6 seat-- ing in an opening through which the cable passes. This opening communicates with a lat eral slot I! provided in the packing support member so that when the split bushing is removed the packing support member may be slipped laterally onto or away from the cable.

The packing support member 2 carries a packing unit l8 which includes a split base ring 19, the half-section of which is in the form of a symmetrical trapezoidwith its shorter side uppermost. Fitted over the base ring are a series of chevron packing rings 20 having radially outer and radially inner downwardly directed lips 2| and 22. The inner lips of the packing rings 20 bear against a split sleeve 23 formed of rubber or, preferably, synthetic rubber of a type impervious to oil, such as neoprene, ihe chevron packing rings may likewise be formed of such material or may be made of leather. The packing unit includes a top ring 24 which is also split and the under side of which is complementary to the packing rings 26.

The packing unit is held in place by a top plate 25 and bolts 26. The bolts extend downward through the top plate, the top ring, chevron packing rings and base ring, and into the upper end 3 of the packing support member 2. The top plate 25 is provided with a central opening for the passage of the cable C, this opening being provided with a split bushing 21 and intersected by a radial slot 28 so that when the split bushing 2| is removed the top plate may be slipped laterally onto or off the cable. The split bushing 21 is normally held in place by a retainer ring 29.

Operation of the automatically releasing well head is as follows: When the head is assembled around a cable above the well tool the parts appear as shown in Figure 2. The packing unit is tightened just sufiiciently to effect a seal and the internal pressure of the well against the lips of the chevron packing rings maintains the seal. Leakage is prevented around the bolt by providing downwardly directed pressure lips around the bolt openings in the packing rings. As stated hereinbefore, the well head is mounted on the well casing several feet above a conventional valve. Normally this valve is open and, consequently, the well tool may be raised and lowered in the well casing. When it is desired to remove the well tool the tool is lifted until within the upper section of the well, thereupon the casing valve is closed so that the upper section of the casing is no longer subject to the well pressure. If desired, a suitable bleeder valve may be provided in this section of the casing to relieve the internal pressure against the well head. It should be pointed out that such arrangement of easing valve and bleeder valve, in combination with a packing well head, is conventional. Previous well heads of this type, however, required disassembly before the well tool'could be removed from the casing. In the construction herein il lustrated it is merely necessary, after relieving the pressure in the upper section of the casing, to pull upwardly on the cable until the gun perforator or other well tool engages the base plate H. Upward force on the base'plate compresses the spring l2 until the release channel it in the keeper mandrel 9 is brought opposite the keeper segments 6. ihese snap inward, out of engagement with the latch recesses 1, thereby releasing all of the parts contained within the housin I. These internal parts, which might be termed broadly the packing assembly, are then lifted by the cable head as shown in Figure 1.

The entire packing assembly, comprising all of the parts normally contained within the housmg l, is capable of being removed from the cable without necessitating disconnection of the cable head E. The various parts of the packing assembly are either split, as in the case of the bushings l6 and 21, base ring l9, top ring 24, chevron packing rings 20, split sleeve 23, and retainer ring 29, or the parts are provided with slots as is the case with the base plate I l, packing support member 2, and top plate 25. The keeper mandrel 9 need not be split as it is large enough to fit over the head E of the cable and the spring I2 is capable of being threaded onto or ofi of the cable.

It is, of course, not necessary to assemble and disassemble the various parts every time the well tool is removed from the well casing. All of the parts of the packing assembly remain intact as shown in Figure 1, and when the gun perforator or other well tool is again lowered into the well casing the packing assembly is forced downward until the spring I2 is again compressed and the latch segments 6 can move into the release channel l9. Normally the packing assembly can be returned to the position shown in Figure 2 without releasing the bolts which provide the initial compression on the packing unit. However, it is a simple matter to back these bolts off a few turns so that the packing unit fits more readily into the housing I. Reinsertion of the internal parts of the packing assembly is facilitated by providing an internal taper 30 on the housing as shown in Figures 2 and 3.

Various changes and alternate arrangements may be made within the scope of the appended claims. in which it is my intention to claim all novelty inherent in the invention.

I claim:

1. A releasable packing head for wells, comprising: a tubular housing adapted to be secured in the upper end of a well casing, its inner surfaces having serrated latching channels formed therein and a smooth bore abovesaid channels forming a packing face; a supporting structure including a cylindrical portion axially sli dable in said tubular housing, and latching. elements carried by said cylindrical portion having radially extending serrations engageable with said channels; a packing unit secured on the top portion of said supporting structure and sealingly but slidably engageable with said packing face, said packing unit having an axial opening therethrough adapted to admit slidably but seal around an instrumentality intended for movement in such casing; means normally engageable with said latching element for holding said latching element in engagement with said channels, thereby to secure said packing unit against axial movement in said housing, said means being engageable from within said casing by said instrumentality for movement clear of said latching element, thereby to release said packing unit for withwrawal axially from said housing.

2. A construction as set forth in claim 1 housing; end plates shaped in conformity with said sealing rings; and means for placing said sealing rings under initial nominal compression.

3. A releasable packing head for wells com: prising: a tubular housing adapted to be secured in the upper end of a well casing; a sealing unitaxially sli dably contained in said housing, said unit having a sleeve of rubber-like material adapted to make a slidable seal around the surface of an instrumentality extending through said housing into said casing; a flexible, annular ring carried by said unit and surrounding said sleeve, said ring having flexible lips extending axially from the inner and outer edges thereof, the inner lips being in sealing engagement with said sleeve and the said outer lips being in axially slidable sealing engagement with the interior of said housing; locking means for retaining said unit against axial sliding movement in said housing; and means associated with said locking means and actuatable from within said housing by said instrumentality for releasing said locking means to free said unit for axial sliding move ment and withdrawal from said housing with said instrumentality.

4. A releasable packing head for wells comprising; a tubular housing adapted to be secured in the upper end of a well casing; a sealing unit axially slidably contained within said houlsing, said unit having a sleeve of rubber-like material adapted to make a slidable seal around the surface of an instrumentality extending through said housing into said casing; a flexible, annular ring carried by said unit and surrounding said sleeve, said ring having flexible lips extending axially from the outer edges thereof, the said outer lips being in axially slidable sealing engagement with the interior of said housing; looking means for retaining said unit against axially sliding movement in said housing; and means associated with said locking means and actuatable from within said housing by said instrumentality for releasing said locking means to free said unit for axial sliding movement and withdrawal from said housing with said instrumentality.

5. A releasable packing head for wells comprising: a tubular housing adapted to be secured in the upper end of a well casing; a sealing unit axially slidably contained within said housing, said unit having a sleeve of rubber-like material adapted to make a slidable seal around the surface of a wire line extending through said housing into said casing; a flexible, annular ring carried by said unit and surrounding said sleeve, said ring having flexible lips extending axially from the inner and outer edges thereof, the inner lips being in sealing engagement with said sleeve and the outer lips being in axially slidable sealing engagement with the interior of said housing; locking means for retaining said unit against axial sliding movement in said housing; and means associated with said locking means and actuatable from within said housing by said wire line for releasing said locking means.

6. A releasable packing head for Wells comprising: a tubular housing adapted to be secured in the upper end of a well casing, said housing having an inner cylindrical bore coaxial with said housing; a packing assembly axially sliclable in said bore and having an axial opening therethrough for passage of an instrumentality into said well casing, said packing assembly including a cylindrical packing support member and an annular packing unit secured on the top portion of said packing support member, said packing unit having an outer periphery in sli dable sealing engagement with said cylindrical bore and an inner periphery for slidable sealing engagement with such instrumentality extending through said axial opening; means for normally locking said packing assembly in said housing against axial sliding movement therein; and means engageable from Within said housing by such instrumentality for releasing said locking means to permit axial movement and withdrawal of said packing assembly from said housing along with such instrumentality.

7. A construction as set forth in claim 6 wherein said packing unit includes: a sleeve of rubberlike material fitting around said instrumentality; a series of sealing rings, each having radially inner and radially outer pressure responsive lips directed axially toward the interior of the housing, the inner lips sealing against said sleeve, and the outer lips sealing against the surface of the bore of said housing; end plates shaped in conformity with said sealing rings; and means for placing said sealing rings under initial nominal compression.

LORRAIN D, MEDDICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

